There is a scene towards the middle of the movie when Jack the Ripper is talking to his manservant or driver. The driver is clearly upset by all of the murders he has helped to commit, as he is shaking, and is asking Jack over and over again why they have to keep killing. There is a close-up on the driver's face for quite some time, and his ears are clearly visible. Throughout the entire movie, the driver has had a mangled right ear, and has been shown countless times. However, in this particular scene, his ears are both very normal, and look as if they had never been hurt before! Oops!

At first I thought his ear was just shaped funny from wearing that hat. Drivers back then would have their ears bent from wearing those hats all day. But you're very right. He has a cut in his ear that wouldn't have healed for years. And it would've still had quite the scar.